Shutter for cameras



March 8, 1960 YASUHISA MATSUDA 2,927,519

SHUTTER FOR CAMERAS Filed April 23, 1956 r 2 Sheets-Sheet 1 March 1960 YASUHISA MATSUDA 2,927,519

SHUTTER FOR CAMERAS 2 Sheets-Sheet 2 Filed April 23, 1956 4 0 F 0 r r 0 a 1 m 5 6 2 1 1 #MVA fll SHUTTER FOR CAMERAS Yasuhisa Matsuda, Tokyo, Japan Application April 23, 1956, Serial No. 579,881 Claims priority, application Japan April 26, 1955 3 Claims. (Cl. 95-55) This invention relates to a shutter for cameras, more particularly a shutter of the focal plane type, and has for its object to provide a shutter which is simple in construction, economical to manufacture, can be readily assembled, and can be operated at high speed in a reliable manner.

The shutter according to this invention comprises a plurality of closing vanes which are slidable with respect to each other and to the frame of the camera, a pair of rocker arms to which said closing vanes are connected at different points on said rocker arms, a driving bar operatively connected to said rocker arms and normally urged toward one direction, a plurality of opening vanes which are slidable with respect to each other and to the frame of the camera, another pair of rocker arms to which said opening vanes are connected at different points on said second pair of rocker arms, and a second driving bar connected to said second pair of rocker arms.

The invention will now be more fully described in connection with the accompanying drawing in which:

Figure l is a front view of a shutter made in accordance with this invention, the shutter vanes being in closed position and the driving bars being in the set positron;

Figure 2 is a similar view showing the shutter released and with the opening vanes opened;

Figure 3 is another similar view showing the closing vares completed closed immediately after an exposure; an

Figure 4 is a vertical section taken along line IV-IV of Figure 1.

Referring now to the drawing in detail, the reference numerals 1a and 1b designate the camera aperture closmg plates or vanes made of thin sheet material and each having a pair of oblong slots 2, 2' and 4, 4", respectively. As shown in Figures 1 and 2, said slots 2 and 4 are engaged by pins 3 and 5 respectively provided on a rocker arm 6, and the slots 2' and 4 are engaged by pins 3' and 5' respectively, provided on another rocker arm 6'. By said rocker arms 6 and 6 the closing vanes 1a and 1b are normally held in a superposed position. Said rocker arms 6 and 6' are pivoted as at 7 and 7', respectively, and on said rocker arms the distance between said pivot 7 or 7' and the pin 3 or 3 are different from the distance between the pivot 7 or 7 and the pin 5 or 5. Each of the rocker arms 6 and 6' is in the form of a bell crank, and their shorter arms are provided with oblong slots 8 and 8 respectively. The driving bar is connected to said shorter arms of the bell cranks 6 and 6' by means of pins 9 and 9 engaging with said slots 8 and 8'. Said driving bar 10 is normally urged toward the right by means of a suitable spring (not shown), but when the shutter is set by moving said driving bar to the left the rightward movement thereof is prevented by means of a pivotally mounted hook 21.

m r d St e Pat n 0 In the lower half of the shutter, there are two camera aperture opening vanes or plates 11a and 11b sumlarly made of thin sheet material. These openmg vanes are similarly provided with a. pair of oblong slots 12, 12' and 14, 14', respectively. Said slots 12 and 14 are engaged by pin 13 and 15 respectively, provided'on a driving rocker arm 16, and the slots 12 and 14 are engaged by pins 13' and 15, respectively, provided on another rocker arm 16'. By said driving rocker arms the opening vanes 11a and 1112 are normally held in an extended position, only a portion being in superposed position,

thus wholly closing the exposure area or aperture 22. Said rocker arms 16 and 16' are pivoted as at 17 and 17', respectively. On said rocker arms, the distance be-H tween said pivot 7 or 7' and the pin 13 or 13 are d1f-.

ferent from the distance between the pivot 17 or 17 and the pin 15 or 15'.

bell cranks 16 and 16' by means of pins 19 and 19' engaging with said slots 18 and 18. Said driving bar 20 is normally urged toward the right by means of a suitable ton through a-suitable mechanism (not shown), and are.

so arranged that when the shutter button is manipulated the book 21 for the opening vanes is disengaged from the driving bar 20, thereby the latter is released and moved toward the right by the action of the spring (not shown), and the driving rocker arms 16 and 16' are turned inwardly and downwardly. Thus, the opening vanes 11a and 11b are moved downwardly, sliding with respect to each other and to the frame of the camera. As the radius of curvature of the movement of the pins 13 and 13' is larger than that of the pins 15 and 15', the movements of the vanes 11a and 11b are different, the vane 11a moving faster than the vane 11b, and at the lower extremity of the movement of two vanes come to just superposed position as shown in Figure 2. After the lapse of a predetermined time interval after the said opening vanes start their opening movement, which time interval is determined by means (not shown of ony suitable mechanism well known in the art, the hook 21 for the driving bar It is disengaged from the latter, thereby the bar 10 is moved toward the right by the action of the spring (not shown), turning the rocker arms 6 and 6 inwardly and downwardly, whereby the closing vanes are moved downwardly as shown in Fig. 3. As the radius of curvature of the movement of the pins 3 and 3' with reference to the pivots 7 and 7' is larger than that of the pins 5 and 5', the closing vane 1a which has been superposed upon the other closing vane 11) now slides along the latter during the downward movement of the vanes, thus the two vanes completely close the whole exposure area 22 at the end of their downward movement, only a portion thereof remaining in a superposed position, as shown in Figure 3.

While in the drawing each of the closing vanes and the opening vanes is illustrated as divided into two sections, it is to be noted that they may be divided into three or more sections.

From the foregoing, it will be seen that according to this invention all shutter vanes are guided and operated Each of the rocker arms 16 and 16'. is in the form of a bell crank, and their shorter arms are provided with oblong slots 18 and 18' respectively. The driving bar 20 is connected to said shorter arms of the by means of the operating means arranged symmetrically on both ends thereof, so that the vanes or plates move linearly, whereby an extremely high speed operation may be attained.

What I claim is:

l. A high-speed focal plane shutter mechanism for a camera provided with an exposureapertnre comprising, a first plurality of spaced plates disposed in substantially parallel planes and on one side of the exposure-aperture so as to be clear thereof, a second plurality of plates disposed in substantially parallel planes in partially over lapping relationship and closing the exposure-aperture, first means selectively operable to move the second plurality of plates simultaneously along substantially linear paths including pivoted means operably connected to said second plurality of plates for moving each at separate speeds clear or" the exposure-aperture in substantially a same interval of time thereby to open the exposure-aperture for taking an exposure, second means for subsequently moving the first plurality of plates simultaneously along substantially linear paths and including means operably connected to the last mentioned plates for moving each in substantially a same interval of time at separate speeds into a partially overlapping relationship closing the exposure-aperture, and shutteroperating means for selectively operating the first and second means sequentially in timed relationship.

2. A high-speed focal plane shutter mechanism for a camera provided with an exposure-aperture comprising, a first pair of spaced plates disposed in substantially parallel planes and normally above the exposure-aperture, a second pair of plates disposed in substantially parallel planes in partially overlapping relationship and closing the exposure-aperture, first means comprising at least one pivoted arm for selectively moving the second pair of plates simultaneously along substantially linear paths including means operably connecting said arm to the second pair of plates for moving them at separate speeds and clear of the exposure-aperture in substantially a same interval of time threby to open the exposure-aperture for taking an exposure, second means comprising at least another pivoted arm for subsequently moving the first pair of plates simultaneously along substantially linear paths and including means operably connecting said other arm to said first pair of plates for moving them in substantially a same interval of time at separate speeds into a partially overlapping relationship and jointly closing the exposure-aperture in said same interval of time.

3. A high-speed focal plane shutter mechanism for a camera provided With an exposure-aperture comprising, a first set of spaced plates disposed in substantially parallel planes, means releasably holding the first set of plates in an exposure-aperture opening position, first means constantly biasing the first set of plates in a direction for closing the exposure-aperture when the shutter mechanism is set, a second set of plates disposed in substantially parallel planes in partially overlapping relationship and closing the exposure-aperture when the shutter mechanism is set, means releasably holding the second set of plates in said exposure-aperture closing position when the shutter mechanism is set, second means constantly biasing the second set of plates in a direction for opening the exposure-aperture when the shutter mechanism is set, means comprising at least one pivoted arm cooperating with said first biasing means for selectively moving the second set of plates simultaneously along substantially linear paths corresponding substantially with the planes in which the plates are disposed and including means operably connecting said one arm to the first set of plates for moving each at separate speeds so as to move them in a same interval of time jointly clear of the exposure-aperture, and means corn prising at least another pivoted arm cooperating with said second biasing means for moving the first set of plates subsequent to the movement of the second set of plates and simultaneously along substantially linear paths corresponding substantially with the planes in which the plates are disposed including means operably connecting said other arm to the second set of plates for moving each in a same interval of time at separate speeds into a partially overlapping relationship closing e exposure-aperture.

References Cited in the file of this patent UNITED STATES PATENTS 2,664,800 Mayo Jan. 5, 1954 

